Electric switches

ABSTRACT

This invention relates to electric switches which are suitable for use as a trigger switch in a fuel injection system for a spark ignition internal combustion engine, in order to determine the instant of opening of one or more electrically actuated fuel injection valves. The invention provides the combination of an ignition distributor and contact breaker assembly with an electric switch having a movable member for effecting operation of the switch, the arrangement being such that rotation of a part of the ignition distributor causes movement of the movable member of the switch to effect its operation. Embodiments are described wherein the electric switch comprises one or more magnetically operable reed contact switches in combination with one or more magnet members for actuating the reed contact switch or switches.

United States Patent [54] ELECTRIC SWITCHES 6Claims,3Drawing Figs.

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[56] References Cited UNlTED STATES PATENTS 3,087,030 4/1963 Shenabow..200/l9 (M) UX Primary Examiner-J R. Scott Attorney-Holcombe, Wetherill& Brisebois ABSTRACT: This invention relates to electric switches whichare suitable for use as a trigger switch in a fuel injection system fora spark ignition internal combustion engine, in order to determine theinstant of opening of one or more electrically actuated fuel injectionvalves. The invention provides the combination of an ignitiondistributor and contact breaker assembly with an electric switch havinga movable member for effecting operation of the switch, the arrangementbeing such that rotation of a part of the ignition distributor causesmovement of the movable member of the switch to effect its operation.Embodiments are described wherein the electric switch comprises one ormore magnetically operable reed contact switches in combination with oneor more magnet members for actuating the reed contact switch orswitches.

- PATENTEU M20197] 3594518 SHEET 2 (IF 2 ELECTRIC SWITCHES The presentinvention relates to electric switches which are suitable for use as atrigger switch in a fuel injection system for a spark ignition internalcombustion engine, in order to determine the instant of opening of oneor more electrically actuated fuel injection valves.

From one aspect the invention provides the combination of an ignitiondistributor and contact breaker assembly for a spark ignition internalcombustion engine, and an electric switch including a movable member foreffecting operation of said switch, the arrangement being such thatrotation of a part of the ignition distributor causes movement of themovable member of said switch to effect operation of said switch.

From another aspect the invention provides an ignition distributor foran engine comprising a distributor body containing a contact breakerassembly for initiating ignition pulses, a unit comprising an electricswitch adapted to operate as a trigger switch for a fuel injectionsystem, said unit including a stationary part mounted on the distributorbody and a rotatable portion carrying a movable operating member forsaid switch and which is connected to a drive shaft in the distributorbody, a distributor cap mounted on the unit and containing contacts anda rotor arm to enable said ignition pulses to be distributed via saidcontacts to spark ignition devices, said rotor arm also being connectedto the rotatable portion of said unit. The electric switch may be of thetype described in copending application Ser. No. 767,218 and compriseone or more magnetically operable reed contact switches in combinationwith one or more magnet members for operating the reed contact switch orswitches, either by relative movement between the reed contact switch orswitches and the magnet member or members, or by providing a relativelymovable magnetic shunt member between the or each reed contact switchand its operating magnet member.

The invention will now be further described by way of example withreference to the accompanying drawings, in which:

FIG. 1 is a section on the line I] in FIG. 2 of one embodiment of theinvention,

FIG. 2 is a plan view of the same embodiment with the distributor capremoved, and

FIG. 3 is a sectional view, similar to FIG. 1, of a further embodiment.

Referring to FIGS. 1 and 2, a distributor comprises a body 1 containinga contact breaker assembly generally indicated at 2 and which is adaptedto be connected to the low-tension section of an ignition coil forinitiating the production of hightension ignition pulses in thehigh-tension section of the coil in accordance with well-known practice.The contact breaker assembly comprises a cam 3 mounted on a drive shaft4 which operates to make and break the contact breaker contacts. Thedrive shaft 4 is driven from a spark ignition internal combustion engineto which the device is fitted.

An electric switch, which is basically of the type disclosed in FIGS. 1to 3 of copending application Ser. No. 767,218 forms part of a unithaving a body portion 5 made of a nonmagnetic material such as aplastics material. The lower face 5a of the body is shaped to fit on andlocate with the upper face of the distributor body.

A rotatable hub portion 6 of the unit is keyed on to the upper end ofthe drive shaft 4 and carries a movable member 7 in the form of adish-shaped magnetic shunt e.g. of mild steel, having a rim 7a providedwith a cutout portion 8. The body 5 also carries two diametricallyspaced reed contact switches 9, as well as two magnet members 10 whichare arranged one opposite each of the reed contact switches 9.Connecting tags 16 are provided for making electrical connections to thereed contacts. The upstanding rim 7a of the magnetic shunt member 7 canthus rotate in the gap between each reed contact switch 9 and itsassociated magnet member 10. The upper edge 5b of the body 5 is shapedto receive and locate the lower edge of the distributor cap 11 whichcontains the peripherally disposed distributor contacts 12 and also thecentral high-tension contact 13 which engages with the conductingportion of a rotor arm 14. The latter fits on and is keyed to the upperend of the hub portion 6. The cap 11 is retained in position by thesecuring clips 15.

Upon rotation of the drive shaft 4 the contact breaker assembly 2 androtor arm 14 operate in the normal manner in association with anignition coil to generate and distribute ignition pulses to sparkignition devices of an internal combustion engine, and the hub portion 6drives the magnetic shunt member 7 in rotation so that the reed contactswitches are operated when the cutout portion 8 in the rim 7a comesopposite each reed contact switch, thereby allowing the magnetic fluxfrom the associated magnet to influence the reed contact switch.

FIG. 3 is a sectional view, similar to that of FIG. 1, of a furtherembodiment of the invention. The same reference numerals have been usedfor corresponding parts. As in the previous embodiment, the body 5carries two stationary diametrically spaced reed contact switches 9, butin this embodiment the rotatable hub portion 6 carries a radiallyextending magnet 10a, and the movable member 7 is omitted. In operation,as the hub portion 6 rotates with the drive shaft 4, the magnet 10aoperates each reed contact switch as it passes opposite to it. Thisembodiment is therefore basically similar to that of FIG. 6 of copendingapplication Ser. No. 767,218.

The present invention enables an electric switch as described inapplication Ser. No. 767,218 to be readily incorporated in aconventional type of ignition distributor which is particularlydesirable where the electric switch is to be used to trigger a fuelinjection system on an internal combustion en-' gine including such anignition distributor.

Obviously various modifications and alternative constructions arepossible. Thus the switch unit may comprise only one or more than tworeed contact switches. Moreover the switch unit may be constructed inaccordance with various of the other arrangements disclosed in theaforementioned copending application.

In particular the or each magnet member and the movable member may bemovable together relative to the or each reed switch.

It will also be apparent that the unit may employ other types of triggerdevices besides magnetic reed contact switches, for example magnetic orphotoelectric devices.

I claim:

1. An ignition distributor and contact breaker assembly for a sparkignition internal combustion engine having an electronically controlledfuel injection system, said assembly comprising a distributor bodycontaining a contact breaker for initiating ignition pulses, a shaftrotatably supported in said body and adapted to be driven in timedrelationship with the internal combustion engine, means secured to theshaft for periodically opening and closing the contact breaker, adistributor cap containing a plurality of contacts one of which isadapted to be connected to an ignition coil of the internal combustionengine and others of which are respectively adapted to be connected tospark ignition devices of the internal combustion engine, and a rotorarm arranged to be driven by said shaft and arranged to sequentiallydistribute the ignition pulses from said one contact to the othercontacts, characterized in that there is further provided an electricswitching device for producing timed trigger signals for theelectronically controlled fuel injection system, said switching devicebeing in the form of a unit comprising a housing of plastics materialshaving one of its oppositely disposed faces shaped to fit on and locatewith the face of the distributor body disposed towards the distributorcap and having the other of its oppositely disposed faces shaped toreceive and locate with the underside of the distributor cap, at leastone electric switch fixedly mounted in the annular housing, and a rotarymember arranged to effect periodic opening and closing of the electricswitch whereby to produce said timed trigger signals, the rotary memberincluding a hub portion which fits coaxially between, and is keyed to,said rotor arm and the end of said shaft.

2. Apparatus as claimed in claim I, wherein the electric switchcomprises at least one magnetically operable reed contact switch incombination with at least one magnet member for actuating the reedcontact switch.

3. Apparatus as claimed in claim 2, wherein the magnet member is securedto the rotary member for rotation therewith.

4. Apparatus as claimed in claim 3, wherein the magnet member isdisposed substantially radially of the rotary member.

5. Apparatus as claimed in claim 2, wherein the or each UNITED STATESPATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,594,518 Dated July20, 1971 Inven r( GORDON F. BATES It is certified that error appears inthe aboveidentified patent and that said Letters Patent are herebycorrected as shown below:

[45] Patented July 20, 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR.

ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents FORMPC4050 (ID-69) USCOMM-DC 6O376-F'69 u 5. GOVERNMENT PRINTING orrlcr. I:o-sssqu

1. An ignition distributor and contact breaker assembly for a sparkigniTion internal combustion engine having an electronically controlledfuel injection system, said assembly comprising a distributor bodycontaining a contact breaker for initiating ignition pulses, a shaftrotatably supported in said body and adapted to be driven in timedrelationship with the internal combustion engine, means secured to theshaft for periodically opening and closing the contact breaker, adistributor cap containing a plurality of contacts one of which isadapted to be connected to an ignition coil of the internal combustionengine and others of which are respectively adapted to be connected tospark ignition devices of the internal combustion engine, and a rotorarm arranged to be driven by said shaft and arranged to sequentiallydistribute the ignition pulses from said one contact to the othercontacts, characterized in that there is further provided an electricswitching device for producing timed trigger signals for theelectronically controlled fuel injection system, said switching devicebeing in the form of a unit comprising a housing of plastics materialshaving one of its oppositely disposed faces shaped to fit on and locatewith the face of the distributor body disposed towards the distributorcap and having the other of its oppositely disposed faces shaped toreceive and locate with the underside of the distributor cap, at leastone electric switch fixedly mounted in the annular housing, and a rotarymember arranged to effect periodic opening and closing of the electricswitch whereby to produce said timed trigger signals, the rotary memberincluding a hub portion which fits coaxially between, and is keyed to,said rotor arm and the end of said shaft.
 2. Apparatus as claimed inclaim 1, wherein the electric switch comprises at least one magneticallyoperable reed contact switch in combination with at least one magnetmember for actuating the reed contact switch.
 3. Apparatus as claimed inclaim 2, wherein the magnet member is secured to the rotary member forrotation therewith.
 4. Apparatus as claimed in claim 3, wherein themagnet member is disposed substantially radially of the rotary member.5. Apparatus as claimed in claim 2, wherein the or each magnet member isfixedly mounted in the annular housing adjacent its respective reedcontact switch, and a magnetic shunt member is secured to the rotarymember for rotation therewith, the magnetic shunt member being movablebetween the or each reed contact switch and its respective magnetmember.
 6. Apparatus as claimed in claim 5, wherein the magnetic shuntmember includes an aperture which allows a magnet member to actuate itsrespective reed contact switch only when the aperture is disposedbetween the magnet member and the reed contact switch.